Initial Inspection and Diagnostic Overview

1. CHECK condition of AUX PWR Fuse. If Fuse is open, LOCATE and REPAIR source of overload. REPLACE Fuse.
2. CHECK Grounds G105, G107, and G110 are clean and tight.
3. CHECK for Battery voltage at terminal 16 (CKT 840) of the DATA LINK CONNECTOR. REPAIR if necessary.
4. CHECK terminal 4, CKT 750 and terminal 5, CKT 550 for continuity to ground. REPAIR if necessary.
5. Check for proper connection of Scan Tool to Data Link Connector (DLC).
6. Check for loose or missing terminals at DLC.
7. If VCM is not accessible with a Scan Tool, check for an open in PPL (1807) wire between component and DLC terminal 2.
8. If Electronic Brake Control Module is not accessible with a Scan Tool, check for an open in TAN/WHT (799) wire between component and DLC terminal 12.
9. If Inflatable Restraint Sensing Diagnostic Module is not accessible with a Scan Tool, check for an open in TAN (800) wire between component and DLC terminal 9.
10. Check for proper installation of aftermarket electronic equipment that may affect the integrity of other systems.
^ CHECK for a broken (or partially broken) wire inside of the insulation which could cause system malfunction but prove GOOD in a Continuity/Voltage check with a system disconnected. These Circuits may be intermittent or resistive when loaded, and if possible, should be checked by monitoring for a Voltage drop with the system operational (under load).
^ CHECK for proper installation of aftermarket electronic equipment which may affect the integrity of other system (see Diagnostic Aids for General Troubleshooting Procedures). Diagnostic Aids